Title: Thermal Management in Nanofiber-Based Face Mask

Abstract

Face masks are widely used to filter airborne pollutants, especially when particulate matter (PM) pollution has become a serious concern to public health. Here in this paper, the concept of thermal management is introduced into face masks for the first time to enhance the thermal comfort of the user. A system of nanofiber on nanoporous polyethylene (fiber/nanoPE) is developed where the nanofibers with strong PM adhesion ensure high PM capture efficiency (99.6% for PM 2.5) with low pressure drop and the nanoPE substrate with high-infrared (IR) transparency (92.1%, weighted based on human body radiation) results in effective radiative cooling. We further demonstrate that by coating nanoPE with a layer of Ag, the fiber/Ag/nanoPE mask shows a high IR reflectance (87.0%) and can be used for warming purposes. These multifunctional face mask designs can be explored for both outdoor and indoor applications to protect people from PM pollutants and simultaneously achieve personal thermal comfort.

@article{osti_1369409,
title = {Thermal Management in Nanofiber-Based Face Mask},
author = {Yang, Ankun and Cai, Lili and Zhang, Rufan and Wang, Jiangyan and Hsu, Po-Chun and Wang, Hongxia and Zhou, Guangmin and Xu, Jinwei and Cui, Yi},
abstractNote = {Face masks are widely used to filter airborne pollutants, especially when particulate matter (PM) pollution has become a serious concern to public health. Here in this paper, the concept of thermal management is introduced into face masks for the first time to enhance the thermal comfort of the user. A system of nanofiber on nanoporous polyethylene (fiber/nanoPE) is developed where the nanofibers with strong PM adhesion ensure high PM capture efficiency (99.6% for PM2.5) with low pressure drop and the nanoPE substrate with high-infrared (IR) transparency (92.1%, weighted based on human body radiation) results in effective radiative cooling. We further demonstrate that by coating nanoPE with a layer of Ag, the fiber/Ag/nanoPE mask shows a high IR reflectance (87.0%) and can be used for warming purposes. These multifunctional face mask designs can be explored for both outdoor and indoor applications to protect people from PM pollutants and simultaneously achieve personal thermal comfort.},
doi = {10.1021/acs.nanolett.7b00579},
journal = {Nano Letters},
number = 6,
volume = 17,
place = {United States},
year = {Mon May 15 00:00:00 EDT 2017},
month = {Mon May 15 00:00:00 EDT 2017}
}

ENVIRONMENTAL MANAGEMENT is pleased to announce that Rebecca Efroymson will join Virginia Dale as Co-Editors-in-Chief of the journal. Dr. Efroymson brings extensive expertise in risk assessment and environmental toxicology. Her work has focused on land management, natural resources, water quality, and rare species, with recent work on benefits and risks of energy alternatives. ENVIRONMENTAL MANAGEMENT has been publishing research on the management and conservation of natural resources and habitats since 1976. Articles discuss implications for an international audience and examine a scientific or management hypothesis. As a premier scientific journal in applied and cross-cutting areas, articles come from a varietymore » of disciplines including biology, botany, climatology, earth sciences, ecology, ecological economics, environmental engineering, fisheries, forest sciences, geography, information science, law, management science, politics, public affairs, social sciences, and zoology, most often in combinations determined by the interdisciplinary topic of the study. The journal strives to improve cross-disciplinary communication by making ideas and results available to environmental practitioners from other backgrounds. The goal of ENVIRONMENTAL MANAGEMENT is to present a wide spectrum of viewpoints and approaches, and to this end the journal consists of four main sections. Forum contains addresses, editorials, comments, and opinions about environmental matters. Articles in the Profile section describe and evaluate particular case histories, events, policies, problems, or organizations and their work. Papers in the Research section present the methods and findings from empirical and model-based scientific studies. The section on Environmental Assessment is for articles that cover methods of appraisal, measurement, and comparison. Generally, the debates published in the journal's Forum help construct better environmental research or policies; Research and Assessment sections foster understanding of environmental problems and usually of their solutions; and Profile articles may contribute to either aim, or both. In the event that important differences of opinion cannot be resolved between authors and referees or readers, the Forum section may be used to present a Comment on an article that has recently been published in the journal, which may be followed by the author's Reply. The journal publishes innovative research that both identifies new problems and formulates novel solutions to well-known ones. Articles are accepted from all over the world, as the international dimension is considered especially important. Research reported in the journal ranges from environmental problems that are common to a wide variety of nations to issues that are either of global concern or not limited to national boundaries. The journal provides a way for scientists to share approaches, methods, and experiences among environmental practitioners in many countries, so that the problems and opportunities of our ever more-interdependent planet may be studied in a concerted manner.« less

The ability of disposable half-face masks containing activated carbon to protect against inhaled ozone O/sub 3/ (nominal experimental exposure concentration, 0.5 ppm) was tested using a specially designed mechanical device simulating the breathing of a moderately exercising human, and then tested further by 18 volunteers exposed to O/sub 3/ in a controlled-environment chamber for 2 h with intermittent mild exercise. As a control experiment, masks containing no activated carbon were tested similarly. On the mechanical device, carbon-impregnated masks removed 96 to 98% of ambient O/sub 3/, whereas masks with no carbon removed 32 to 37%. Volunteers experienced typical respiratory irritationmore » and temporary loss of forced expiratory function during O/sub 3/ exposures when they wore the masks without carbon. These untoward effects were substantially reduced when masks containing carbon were worn. Volunteers tolerated the half-masks reasonably well, although some complained of discomfort. Disposable masks may be of significant benefit in protecting sensitive people from O/sub 3/ exposures that they cannot readily avoid by other means.« less

Purpose: To assess the robustness of immobilization using open-face mask technology for linac-based stereotactic radiosurgery (SRS) with multiple non-coplanar arcs via repeated CBCT acquisition, with comparison to contemporaneous optical surface tracking data. Methods: 25 patients were treated in open faced masks with cranial SRS using 3–4 non-coplanar arcs. Repeated CBCT imaging was performed to verify the maintenance of proper patient positioning during treatment. Initial patient positioning was performed based on prescribed shifts and optical surface tracking. Positioning refinements employed rigid 3D-matching of the planning CT and CBCT images and were implemented via automated 6DOF couch control. CBCT imaging was repeatedmore » following the treatment of all non-transverse beams with associated couch kicks. Detected patient translations and rotations were recorded and automatically corrected. Optical surface tracking was applied throughout the treatments to monitor motion, and this contemporaneous patient positioning data was recorded to compare against CBCT data and 6DOF couch adjustments. Results: Initial patient positions were refined on average by translations of 3±1mm and rotations of ±0.9-degrees. Optical surface tracking corroborated couch corrections to within 1±1mm and ±0.4-degrees. Following treatment of the transverse and subsequent superior-oblique beam, average translations of 0.6±0.4mm and rotations of ±0.4-degrees were reported via CBCT, with optical surface tracking in agreement to within 1.1±0.6mm and ±0.6-degrees. Following treatment of the third beam, CBCT indicated additional translations of 0.4±0.2mm and rotations of ±0.3-degrees. Cumulative couch corrections resulted in 0.7 ± 0.4mm average magnitude translations and rotations of ±0.4-degrees. Conclusion: Based on CBCT measurements of patients during SRS, the open face mask maintained patient positioning to within 1.5mm and 1-degree with >95% confidence. Patient positioning determined by optical surface tracking agreed with CBCT assessment to within 1±1mm and ±0.6-degree rotations. These data support the use of 1–2mm PTV margins and repeated CBCT to maintain stereotactic positioning tolerances.« less

Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensingmore » limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0129156414500062« less